Applied acoustics in the built environment is focused on the development and commercial adoption of techniques and technologies resulting from research in applied acoustics:
- Developing standard methodologies in the areas of Rain Noise, Building Envelope design, Low Frequency Noise, Structure-borne Sound, Surface Acoustic Diffusion and Multi-porous materials;
- The adoption of standard practice in local and national government bodies in the UK and internationally, in test houses, the construction industry, consultancies and extending into automotive and aerospace industries;
- Commercial application of technologies deriving from the research in reducing environmental noise, improving environmental and performance acoustics, bringing economic and environmental benefit.
Innovation in acoustic technologies
Dr Mags Adam, Professor Jamie Angus, Professor Trevor Cox, Dr Andy Elliott, Professor Yiu Lam, Professor Andy Moorhouse, Dr Dave Saunders (retired 2003), Dr Olga Umnova and Dr David Waddington have developed a range of applications for acoustics research including: rain noise, building envelope, low frequency sound, structure-borne sound, surface diffusion and porous materials. Each are implemented in standard practice in the built environment sector with subsequent take up in the automotive, aerospace, mechanical and construction industries:
- Rain noise: A test method for rain noise formed the basis for an ISO standard (ISO 140-18: 2006); becoming the standard method worldwide for assessment of rain impact noise by roof and roof-light structures. Government guidance on the acoustic design of educational buildings; BB93, which includes a methodology for predicting noise for different intensities of rainfall, forms part of UK Building Regulations, requiring specific design measures for rain noise assessed according to the standard, compulsory in all new schools built since 2003. Since 2012, rain noise assessment using ISO140-18:2006 has also been included in the ‘Acoustic Performance Standards for the Priority Schools Building Programme’.
- Building envelope: Salford models for sound insulation of profiled metal cladding constructions were implemented into a PC based software package which was adopted by members of the Metal Cladding and Roofing Manufacturers Association (MCRMA) in 1995. Major UK construction and manufacturing companies have adopted the models. The software package is still in use by the majority of MCRMA members, a remarkable achievement given the rapid pace of developments in the industry and software over that period, with further updating of the models commissioned by the MCRMA in July 2013.
- Low frequency noise: Guidelines for assessment of low frequency noise have been adopted as a standard approach for low frequency noise complaints by Environmental Health Officers within UK local authority noise enforcement teams. The guidelines form a key part of the strategy for dealing with noise complaints within the Environment Agency, frequently cited in public enquiries. University of Salford training in the use of the procedure was commissioned by the Environment Agency in 2012 for their noise specialists.
- Structure-borne sound: A new reception plate method for characterisation of sources of structure-borne sound has been adopted as a European standard method for sound sources in buildings BS EN 15657-1:2009 Acoustic properties of building elements and of buildings. Laboratory measurement of airborne and structure borne sound from building equipment. This standard is called up by another standard EN12354-5: 2009 Building acoustics — Estimation of acoustic performance of building from the performance of elements Part 5: Sounds levels due to the service equipment for prediction of sound levels from services equipment.
- The Salford team was commissioned by Defra, CLG and DECC to employ the in-situ blocked force method in developing guidelines for prediction of structure-borne sound from building-mounted wind turbines for stimulating renewable energy generation by the removal of planning restrictions where possible. In 2009 a set of guidelines employing the method suitable for adoption by local authorities was drawn up and published on the Defra website, forming the basis of standard practice in the UK.
- Room Acoustic Diffusers: research has led both to an international measurement standard and to new designs of diffusers ISO 17497-2. As convener of ISO Working Group WG25 Cox contributed to the adoption of the internationally agreed measurement method for diffusers, his diffuser designs can be found hundreds of rooms worldwide, examples include Sony M1 studios in New York, Cinema in Seattle and the Hummingbird Centre in Toronto. Diffuser designs have been exploited commercially using the Binary Amplitude Diffusor/Absorber (BAD), proposed by Angus, which simultaneously provides uniform sound diffusion at high and mid band frequencies.
- Multi-scale porous materials: Research demonstrated the ‘enhanced compliance’, of multi-scale porous materials, specifically, activated carbon, to provide significant acoustic benefits, for example in sound insulation by making cavities appear acoustically larger than their physical size. The research outcomes led to the filing of two patents and formation of the spinout company CarbonAir in 2012. The company has secured licence contracts, including with a specialist manufacturer of acoustic treatment materials for studio and home theatre applications and a 12 year license agreement with a German Tier1 supplier to exploit multi-porous materials in car suspensions.